Conventional cameras generally include a lens, an image sensor and a controller communicatively coupled to the image sensor. As is generally understood, the lens is typically configured to receive light reflected from an object being imaged and project such light onto the image sensor. The image sensor may, in turn, be configured to detect the light projected from the lens to permit a digital image of the object to be generated. For example, the image sensor may be configured to convert the detected light into analog signals. The analog signals may then be converted by the camera's controller to digital data that can be used to generate a digital image.
With a typical camera lens, the focal distance of the lens varies with changes in temperature, thereby resulting in variations in the exact focus of the camera over small temperature ranges. To address this problem, athermal lens designs have been developed that utilize various different material combinations in an attempt to maintain the focus of a camera over a given temperature range. However, such athermal lens designs are typically quite complex and very expensive. Moreover, these designs fail to take into account that other operating parameters associated with the lens, such as air pressure, humidity and distance to the reflecting object, may also result in variations in the focal distance of the lens. This particularly true for vented lenses used in aerial photography, as such lenses typically included internal air spaces that change density with changes in pressure and/or humidity.